The present invention relates to motor vehicle braking devices, particularly devices comprising a mechanical hand brake actuator.
Such a braking device comprises in the conventional way a hydraulic ram intended to press a brake pad firmly against a brake disc incapable of rotating independently of a wheel of the vehicle. The hydraulic ram comprises a ram cylinder and a ram piston capable of sliding in the cylinder.
Usually, the translational movement of the ram piston is brought about by rotary control means, via means that convert the rotational movement of these control means into a translational movement of the piston. These conversion means are carried by a mechanical actuator cartridge for a brake, which cartridge is intended to be positioned in the ram cylinder between the rotary control means and the piston.
Thus, the prior art, particularly ITTO 2001 0681 (A1), discloses a cartridge of the type comprising:                a cartridge body with an overall shape exhibiting symmetry of revolution about an axis, incapable of rotating independently of the cylinder,        a control shaft, housed in the cartridge body, on the one hand incapable of rotating independently of a rotary control plate and, on the other hand, intended to rotate as one with the rotary control means,        a push plate, housed in the cartridge body, collaborating, on the one hand, with the control plate via means that convert the rotational movement of the control plate into a translational movement of the push plate, and on the other hand intended to collaborate with the ram piston to drive the translational movement of this ram piston,        elastic means of compressing the push plate towards the control plate,        a cage for holding the elastic means, the elastic means extending between a first seat borne by the cage and a second seat borne by the push plate, in which:        the cartridge body comprises at least one projection for attaching the cage to the body, and the cage comprises at least one axial tab comprising an attachment orifice capable of collaborating with the attachment projection to attach this cage to the cartridge body,        the cage is capable of rotational movement about the axis of the cartridge body, between an attachment position in which the attachment orifice collaborates with the attachment projection, and a release position in which the cage is released from the body,        the cartridge body comprises at least one first circumferential limit stop for limiting the rotation of the cage, the axial tab of the cage being capable of collaborating with the first limit stop when the cage is in its release position.        
When the cartridge is being stored or being mounted in the cylinder, the elastic compression means are held in the cartridge by the cage, which is attached to the cartridge body.
When the cartridge is inserted in the cylinder, the cage is turned from its position of attachment to the body to its position of being released from this body. During this change in position, the axial tab is deformed by a slight radial movement as it rises up to rest against the attachment projection.
This axial tab is usually provided with a hook, intended to collaborate with an opening, for example a peripheral slot formed in the ram cylinder. Thus, when the axial tab is resting against the attachment projection, the hook collaborates with the corresponding opening so that the cage is attached to the cylinder.
It will be noted that when the cage is attached to the cylinder, the tab rests against a surface of reduced surface area, consisting of the attachment projection, which is of a small size. Thus, there is a risk that the tab will become detached or deformed, leading to premature cage wear.